Abstract

Virus diseases are one of the most devastating barriers for a successful and commercial production of tomato (Lycopersicon esculentum). The study aims to review the status of selected virus diseases of tomato and to overview the advancement in host resistance against the virus diseases. Tomato yellow leaf curl virus (TYLCV), Tomato spotted wilt virus (TSWV), Tobacco mosaic virus (TMV), Tomato mosaic virus (ToMV), Cucumber mosaic virus (CMV) and Tomato mottle virus (ToMoV) are the most devastating virus diseases of tomato. Various cultural, integrated, resistant and chemical methods (against insect vectors) have been developed to reduce the yield loss due to virus diseases; however, only host resistance were effective to some extent. The wild families of tomato Lycopersicon pimpinellifolium, Lycopersicon peruvianum, Lycopersicon cheesmani, Lycopersicon peruvianum and Lycopersicon pimpinellifolium have robust resistance against Tomato yellow leaf curl virus. Similarly Pimpertylc-J-13, Chepertylc-92 and hybrid Mirella are some other lines which have resistance against TYLCV of Tomato. Lycopersicon pimpinellifolium, Lycopersicon hirsutum, Lycopersicon chilense and Lycopersicon peruvianum have been identified having resistant characteristics against Tomato spotted wilt virus. Tomato varieties Pearl Harbour and Manzana have strain-specific resistant. Several tomato hybrids having Sw-5 gene were resistance against Tomato Spotted Wilt Virus. The dominant genes Tm-22 and Tm-2 which is an allelic of Tm-22 have considerable level of resistance against Tobacco mosaic virus in different regions of Asia. Transgenic line 4174 have ample resistance against mechanical infections by TMV. Several wild species of Tomato have exhibited resistance against Cucumber mosaic virus; however, due to polygenic nature of the resistance and plant infertility problems the development of durable resistant varieties against the disease is not much successful. Durable resistance to Tomato mottle virus has been obtained from different wild species of Lycopersicon spp. The treatment of Tomato plants with plant growth-promoting rhizobacteria (PGPR) augmented the induced resistance against Tomato mottle virus. Latest researches have been concentrated on genetic engineering which focus on the manipulation, modification and inclusion of resistant genes from other species, none host species and also from the pathogen itself; however, the worries on negative impacts of transgenic crops must be cleared by further research and findings.

Provvidenti R. and Gonsalves D. (1995)., Inheritance of resistance to cucumber mosaic virus in a transgenic tomato line with the coat protein gene of the white leaf strain., Journal of Heredity, 86, 85-88.